|Número de publicación||US6212883 B1|
|Tipo de publicación||Concesión|
|Número de solicitud||US 09/518,409|
|Fecha de publicación||10 Abr 2001|
|Fecha de presentación||3 Mar 2000|
|Fecha de prioridad||3 Mar 2000|
|Número de publicación||09518409, 518409, US 6212883 B1, US 6212883B1, US-B1-6212883, US6212883 B1, US6212883B1|
|Cesionario original||Moon-Ki Cho|
|Exportar cita||BiBTeX, EndNote, RefMan|
|Citas de patentes (17), Citada por (49), Clasificaciones (17), Eventos legales (6)|
|Enlaces externos: USPTO, Cesión de USPTO, Espacenet|
(a) Field of the Invention
The present invention relates to a method and apparatus for treating exhaust gas produced from the combustion of fuels, and more particularly, to such a method and apparatus wherein the reduction of pollutants is achieved by the use of ozone and water vapor.
(b) Description of the Related Art
Internal combustion engines, which operate by the controlled combustion of hydrocarbon fuels, produce exhaust gases containing the complete combustion products of CO2 and H2O, and also pollutants from incomplete combustion, such as unburnt hydrocarbons (HC) as well as CO, which is a direct poison to human life. Further, due to the very high temperatures produced by the burning of hydrocarbon fuels, thermal fixation of nitrogen from the air results in the detrimental formation of nitric oxides (NOx).
The quantity of pollutants varies with many operating conditions of the engine, but it is influenced predominantly by the air-to-fuel ratio in the combustion chamber. Conditions conducive to reducing carbon monoxide and unburnt hydrocarbons (a fuel mixture just lean of stoichiometric as well as high combustion temperatures) cause an increased formation of NOx, and conditions conducive to reducing the formation of NOx (rich fuel mixture and low combustion temperatures) cause an increase in carbon monoxide and unburnt hydrocarbons in the exhaust gases of the engine. As a result, within the region of stable operation of the internal combustion engine, a significant amount of CO, HC and NOx is emitted into the atmosphere.
There has been a proposed three-way catalysis (TWC) technology to reduce the pollutants of the exhaust gases. The TWC technology comprises the use of precious metals Pt, Rh, and Ce. The basic operation of Pt is to oxidize CO and HC to CO2 and H2O, Rh is primarily responsible for the reduction of NOx, and Ce functions as an emitter of oxygen. The activity of Rh, however, is reduced in a high oxidizing atmosphere, and Rh may react with CeO2 at high temperature, reducing the activity of both.
Reduction technology has also proposed the use of ammonia as a reducing agent and V2O5—TiO2 as a catalyst, but this is likely to exhaust toxic ammonia gas according to the concentration of NOx in the exhaust gas.
Another reducing agent has been proposed using hydrocarbons instead of ammonia in Japanese Laid-Open Patent Application No. 63-100919. A catalyst is used in combination with copper and a porous carrier such as alumina, silica or zeolite. However, this method has drawbacks in that the catalyst is likely to be degraded by SOx.
In view of the prior art described above, it is an object of the present invention to provide a method and apparatus for treating exhaust gas produced from the combustion of fuels.
It is another object of the present invention to provide a method and apparatus for reducing pollutants of incomplete combustion in the exhaust gases treated by the use of ozone and water vapor.
A particularly advantageous feature of preferred embodiments of the present invention is that they can be applied to a variety of different types of internal combustion engines, including, but not limited to, automobiles, trucks, stationary power generators, motor boats and motorcycles.
To achieve these and other objects and features, as embodied and broadly described herein, the invention comprises the steps of:
introducing ozone into the exhaust gas in an ozone contactor which is located downstream from a catalytic converter;
passing the exhaust gas through a muffler having an inlet and an outlet;
introducing water vapor into the exhaust gas prior to the outlet of the muffler; and
passing the exhaust gas through at least a portion of a muffler, thereby reducing at least one pollutant, selected from the group consisting of unburnt hydrocarbons, carbon monoxide and oxides of nitrogen, from a first concentration to a second lower concentration.
According to another aspect of the present invention, an apparatus for treating exhaust gas produced from the combustion of fuels, comprising:
an ozone contactor located downstream from a catalytic converter, for mixing the exhaust gas with ozone;
a muffler having an inlet and an outlet;
a water evaporator for adding water vapor to the exhaust gas; and
a passageway for conducting water vapor into the muffler such that the exhaust gas stream passes through water vapor prior to exhausting from the outlet of the muffler.
Both the foregoing general description and the following Detailed Description are exemplary and are intended to provide further explanation of the invention as claimed.
The accompanying drawings provide a further understanding of the invention and, together with the Detailed Description, explain the principles of the invention. In the drawings:
FIG. 1 is a block diagram illustrating an embodiment of the apparatus of the present invention; and
FIG. 2 is a block diagram illustrating the method of the present invention.
The present invention will be described in detail with reference to the accompanying drawings.
Referring to FIG. 1, one embodiment of an apparatus of the present invention is illustrated generally at 10. The apparatus 10 comprises an ozone contactor 5, ozone generator 2, water evaporator 3 and muffler 6. The ozone contactor 5 is located upstream from a muffler 6 and downstream from a catalytic converter 4. The ozone generator 2 provides the ozone contactor with ozone.
The ozone generator 2 can be either of two basic types: ultraviolet or corona discharge. The ultraviolet type employs gas-discharge lamps which emit bright ultraviolet light (also called “UV” or “black light” lamps) which breaks up atmospheric oxygen and thus creates ozone. Because UV lamps are relatively fragile and bulky, requiring a large housing in ultra-violet type ozone generators, corona discharge type generators are preferably used in the embodiment of the present invention.
The ozone generator 2 of the corona discharge type creates ozone by subjecting air, which is provided from an air filter 1, to a very high electric field. The strong electric field sufficient to break up oxygen molecules is supplied from an inverter, which comprises insulated gate bipolar transistors (IGBT) and a transformer having a winding ratio of 1:10. The high-voltage coil of the inverter is connected to two electrodes such that one goes positive when the other is negative. The two electrodes form a sort of capacitor, and usually comprise two parallel plates, concentric cylinders, or some other geometry which allows for a constant distance between the electrodes. The description of the ozone generator 2 may also be modified to explain similar structures, and further descriptions thereof will not be made.
The ozone generator 2 preferably produces ozone in the amount of 3 grams per hour at 600 Hz, the fixed frequency of the inverter.
The water evaporator 3 may include a vibrator in the form of an electrically operable ultrasonic transducer. The water is made to vibrate by a high-frequency vibrator which causes the water to be atomized. An air stream directed onto the water carries the water vapor into the muffler 6. The water evaporator 3 preferably produces water vapor which has the ratio of condensate water: water vapor=4:1.
The muffler 6 has an inlet and outlet for the exhaust gas stream. A passageway is provided for conducting water vapor produced from the water evaporator 3 into the muffler 6 such that the exhaust gas stream passes through the water vapor prior to exhausting from the outlet of the muffler.
Referring now to FIG. 2, the method of the present invention is illustrated.
The exhaust gas stream, which is already treated by the catalytic converter 4 at a temperature of 300-400° C., enters the ozone contactor 5. In the ozone contactor 5, the exhaust gases are mixed with ozone produced by the ozone generator 2 (Step S1). In this step S1, pollutants comprising unburnt hydrocarbons (HC), NOx, and SOx react with ozone and oxidize into CO2, NO3−, and SO3 2−, respectively. Carbon monoxide (CO) may also oxidize into CO2.
Next, the gas stream passes through the muffler 6 in which water vapor is introduced (Step S2). At least one pollutant in the gas reacts with the water vapor to reduce the pollutants. Specifically, NO3− and S0 3 2− react with the water and turn into HNO3 and H2SO4, respectively. Because HNO3 and H2SO4 are in liquid phase, they are easy to separate from the gas. Accordingly so that the resultant exhaust gas expelled by the muffler 6 is primarily CO2, and the other pollutants are reduced (Step S3).
Table 1 compares the results obtained with and without the apparatus according to the present invention.
With the present
Below 220 ppm
As shown in Table 1, pollutants comprising CO and HC to CO2 and SO2 are remarkably reduced.
It will be apparent to those skilled in the art that various modifications and variations can be made to the device of the present invention without departing from the spirit and scope of the invention. The present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
|Patente citada||Fecha de presentación||Fecha de publicación||Solicitante||Título|
|US3984296 *||13 Sep 1974||5 Oct 1976||Richards John R||System and process for controlling air pollution|
|US4945721 *||14 Abr 1988||7 Ago 1990||Environmental Research International, Inc.||Electromagnetic converter for reduction of exhaust emissions|
|US5121602 *||26 Dic 1990||16 Jun 1992||Mccorvey Allan F||Pollution control apparatus|
|US5223105 *||29 Jun 1990||29 Jun 1993||Arthurson Corporation Pty. Ltd.||Ozone generator|
|US5806305 *||28 Jun 1996||15 Sep 1998||Lockheed Martin Corporation||Method and apparatus for reducing pollutants|
|US5807526 *||14 Oct 1994||15 Sep 1998||Miljevic; Vujo||Device for removal of SO2 and NOx from flue gases by high frequency discharge by Tesla coil or other high voltage and high frequency generator|
|US5863413 *||18 Dic 1996||26 Ene 1999||Litex, Inc.||Method for using hydroxyl radical to reduce pollutants in the exhaust gases from the combustion of a fuel|
|US6012283 *||23 Jun 1998||11 Ene 2000||Lockheed Martin Corp.||Method and apparatus for reducing pollutants|
|US6033462 *||30 Jun 1998||7 Mar 2000||Dekker Vacuum Technologies, Inc.||Multi-chambered air/oil separator|
|US6038853 *||15 Jul 1998||21 Mar 2000||The Regents Of The University Of California||Plasma-assisted catalytic storage reduction system|
|US6038854 *||22 Jul 1998||21 Mar 2000||The Regents Of The University Of California||Plasma regenerated particulate trap and NOx reduction system|
|US6047543 *||24 Jul 1998||11 Abr 2000||Litex, Inc.||Method and apparatus for enhancing the rate and efficiency of gas phase reactions|
|US6048500 *||6 Mar 1998||11 Abr 2000||Litex, Inc.||Method and apparatus for using hydroxyl to reduce pollutants in the exhaust gases from the combustion of a fuel|
|US6153151 *||5 Ago 1999||28 Nov 2000||Moxley; Douglas A.||System and method for generating ozonated water|
|DE4231581A1 *||21 Sep 1992||24 Mar 1994||Siemens Ag||Verfahren zur plasmachemischen Zersetzung und/oder Vernichtung von Schadstoffen, insbesondere zur Abgasreinigung von Verbrennungsmotoren oder anderer mit fossilem Treibstoff betriebenen Maschinen, sowie zugehörige Vorrichtung|
|JPS5870016A *||Título no disponible|
|JPS63100919A||Título no disponible|
|Patente citante||Fecha de presentación||Fecha de publicación||Solicitante||Título|
|US6544485||29 Ene 2001||8 Abr 2003||Sharper Image Corporation||Electro-kinetic device with enhanced anti-microorganism capability|
|US6585935||20 Nov 1998||1 Jul 2003||Sharper Image Corporation||Electro-kinetic ion emitting footwear sanitizer|
|US6588434||2 Jul 2002||8 Jul 2003||Sharper Image Corporation||Ion emitting grooming brush|
|US6632407||25 Sep 2000||14 Oct 2003||Sharper Image Corporation||Personal electro-kinetic air transporter-conditioner|
|US6672315||19 Dic 2000||6 Ene 2004||Sharper Image Corporation||Ion emitting grooming brush|
|US6682707 *||14 Nov 2001||27 Ene 2004||Kiwi Auto Accessories Co., Ltd.||Automobile air filter|
|US6684629 *||1 Oct 2002||3 Feb 2004||Siemens Aktiengesellschaft||Method for checking the conversion capacity of a catalytic element for converting ozone|
|US6709484||8 Ago 2001||23 Mar 2004||Sharper Image Corporation||Electrode self-cleaning mechanism for electro-kinetic air transporter conditioner devices|
|US6713026||5 Dic 2000||30 Mar 2004||Sharper Image Corporation||Electro-kinetic air transporter-conditioner|
|US6749667||21 Oct 2002||15 Jun 2004||Sharper Image Corporation||Electrode self-cleaning mechanism for electro-kinetic air transporter-conditioner devices|
|US6827088||4 Jun 2003||7 Dic 2004||Sharper Image Corporation||Ion emitting brush|
|US6912841 *||10 Jul 2002||5 Jul 2005||Robert Bosch Gmbh||Device and method for exhaust-gas treatment|
|US6948308 *||18 Feb 2003||27 Sep 2005||Johnson Matthey Public Limited Company||Combatting air pollution|
|US6958134||12 Feb 2002||25 Oct 2005||Sharper Image Corporation||Electro-kinetic air transporter-conditioner devices with an upstream focus electrode|
|US7662348||10 Jun 2005||16 Feb 2010||Sharper Image Acquistion LLC||Air conditioner devices|
|US7695690||12 Feb 2002||13 Abr 2010||Tessera, Inc.||Air treatment apparatus having multiple downstream electrodes|
|US7724492||20 Jul 2007||25 May 2010||Tessera, Inc.||Emitter electrode having a strip shape|
|US7767165||3 Mar 2005||3 Ago 2010||Sharper Image Acquisition Llc||Personal electro-kinetic air transporter-conditioner|
|US7767169||22 Nov 2004||3 Ago 2010||Sharper Image Acquisition Llc||Electro-kinetic air transporter-conditioner system and method to oxidize volatile organic compounds|
|US7833322||27 Feb 2007||16 Nov 2010||Sharper Image Acquisition Llc||Air treatment apparatus having a voltage control device responsive to current sensing|
|US7897118||8 Dic 2004||1 Mar 2011||Sharper Image Acquisition Llc||Air conditioner device with removable driver electrodes|
|US7906080||30 Mar 2007||15 Mar 2011||Sharper Image Acquisition Llc||Air treatment apparatus having a liquid holder and a bipolar ionization device|
|US7959869||9 May 2003||14 Jun 2011||Sharper Image Acquisition Llc||Air treatment apparatus with a circuit operable to sense arcing|
|US7976615||12 Mar 2010||12 Jul 2011||Tessera, Inc.||Electro-kinetic air mover with upstream focus electrode surfaces|
|US8043573||8 Feb 2010||25 Oct 2011||Tessera, Inc.||Electro-kinetic air transporter with mechanism for emitter electrode travel past cleaning member|
|US8051643 *||12 Jun 2006||8 Nov 2011||Toyota Jidosha Kabushiki Kaisha||Exhaust gas purification system utilizing ozone|
|US8066851 *||23 Oct 2007||29 Nov 2011||M-I L.L.C.||In-line treatment of hydrocarbon fluids with ozone|
|US8266895 *||11 Abr 2008||18 Sep 2012||Toyota Jidosha Kabushiki Kaisha||O3 production apparatus and exhaust gas purification system for internal combustion engine|
|US8425658||20 May 2011||23 Abr 2013||Tessera, Inc.||Electrode cleaning in an electro-kinetic air mover|
|US8882969||24 Oct 2011||11 Nov 2014||M-I Llc||In-line treatment of hydrocarbon fluids with ozone|
|US20010048906 *||8 Ago 2001||6 Dic 2001||Sharper Image Corporation||Electrode self-cleaning mechanism for electro-kinetic air transporter-conditioner devices|
|US20020134665 *||12 Feb 2002||26 Sep 2002||Taylor Charles E.||Electro-kinetic air transporter-conditioner devices with trailing electrode|
|US20040179981 *||22 Mar 2004||16 Sep 2004||Sharper Image Corporation||Electrode cleaning for air conditioner devices|
|US20040234431 *||25 Jun 2004||25 Nov 2004||Sharper Image Corporation||Electro-kinetic air transporter-conditioner devices with trailing electrode|
|US20040237787 *||30 Abr 2004||2 Dic 2004||Sharper Image Corporation||Electrode self-cleaning mechanism for air conditioner devices|
|US20040251124 *||15 Sep 2003||16 Dic 2004||Sharper Image Corporation||Electro-kinetic air transporter and conditioner devices with features that compensate for variations in line voltage|
|US20040251909 *||23 Jul 2003||16 Dic 2004||Sharper Image Corporation||Electro-kinetic air transporter and conditioner devices with enhanced arching detection and suppression features|
|US20050000793 *||21 Jul 2004||6 Ene 2005||Sharper Image Corporation||Air conditioner device with trailing electrode|
|US20050061344 *||1 Nov 2004||24 Mar 2005||Sharper Image Corporation||Ion emitting brush|
|US20050082160 *||15 Oct 2003||21 Abr 2005||Sharper Image Corporation||Electro-kinetic air transporter and conditioner devices with a mesh collector electrode|
|US20050146712 *||24 Dic 2003||7 Jul 2005||Lynx Photonics Networks Inc.||Circuit, system and method for optical switch status monitoring|
|US20050147545 *||3 Mar 2005||7 Jul 2005||Sharper Image Corporation||Personal electro-kinetic air transporter-conditioner|
|US20050160906 *||23 Mar 2005||28 Jul 2005||The Sharper Image||Electrode self-cleaning mechanism for air conditioner devices|
|US20090184050 *||23 Jul 2009||Barr Dale C||Systems and Methods for Watercraft Having Marine Environment Enhancement Capability|
|US20100064669 *||11 Abr 2008||18 Mar 2010||Toyota Jidosha Kabushiki Kaisha||O3 production apparatus and exhaust gas purification system for internal combustion engine|
|US20100132337 *||11 Mar 2008||3 Jun 2010||Hirohito Hirata||Exhaust gas purification device for internal combustion engine|
|US20100275586 *||28 Nov 2006||4 Nov 2010||Hirohito Hirata||Device for cleaning exhaust gas of internal combustion engine|
|USRE41812||21 Ene 2005||12 Oct 2010||Sharper Image Acquisition Llc||Electro-kinetic air transporter-conditioner|
|EP1712752A2 *||21 Mar 2006||18 Oct 2006||Toyota Jidosha Kabushiki Kaisha||Exhaust gas purifying apparatus and method thereof|
|Clasificación de EE.UU.||60/275, 204/176, 60/310, 422/186.07|
|Clasificación internacional||F01N13/02, F01N3/08, F01N3/28, F01N3/20|
|Clasificación cooperativa||F01N3/0892, F01N2430/04, F01N3/206, F01N3/2882, F01N13/009, F01N2240/38|
|Clasificación europea||F01N3/28D, F01N3/08C, F01N3/20D|
|3 Mar 2000||AS||Assignment|
|30 Sep 2004||FPAY||Fee payment|
Year of fee payment: 4
|30 Sep 2008||FPAY||Fee payment|
Year of fee payment: 8
|19 Nov 2012||REMI||Maintenance fee reminder mailed|
|10 Abr 2013||LAPS||Lapse for failure to pay maintenance fees|
|28 May 2013||FP||Expired due to failure to pay maintenance fee|
Effective date: 20130410